Hand tool for adjusting needle eye laps



July 4, 1967 RINGZELL. ETAL 3,329,001

) HAND TOOL FOR ADJUSTING NEEDLE EYE LAPS Filed July 13, 1964 INVENTORS.

ARTHUR J. RINGZELLI ROMBIN EDWIN AIT 7 United States Patent 3,329,001HAND TOOL FOR ADJUSTING NEEDLE EYE LAPS Arthur J. Ringzelli and Edwin H.Rombin, Chicago, IlL, assignors to Acro Die and Stamping (30., Chicago,111., a corporation of Illinois Filed July 13, 1964, Ser. No. 382,331Claims. (Cl. 72-409) The present invention relates to a tool foradjusting the working size of an improved needle eye lap and moreparticularly to a simple pincer type tool combination that can be usedto expand or correct a wide range of lap sizes as they were or are usedfor different size holes.

Lapping is a surface finishing process commonly used whenever a drilledor reamed hole has to be further processed for close tolerances andsatin finishes. Holes are lapped by reciprocating and progressivelyrotating rodlike tools or laps that fit snugly in the hole and aresupplied with an abrasive compound between the engaging surfaces of thelap and the hole. Laps are generally made from a relatively soft metalso that the abrasive becomes somewhat imbedded in the lap instead of theworkpiece in order to size and finish the wall of the hole. During theprocess the lap becomes worn as the hole is slightly increased in sizethereby making it necessary repeatedly to increase the size of the lapso as to again contact the walls of the hole with a lapping pressurecontact.

A superior lapping tool is found in the needle eye lap characterized bysplit and spread semicylindrical sections extending over a predeterminedlength of solid rod stock. This arrangement has the advantages of a dualresilient action to force the external working faces of the sectionsagainst the walls of the hole and with its reciprocation and progressiverotation not only is an excellent finish provided but the objectionablebell mouth shape is eliminated that occurs in other lapping processessuch as with tapered laps. Since this method is inherently superior toother laps it has long been sought to develop a tool whereby the needleeye sections could be easily adjusted by the use of a simple hand toolthat will fit all sizes and lengths of needle eye laps to spread orclose the two sections accurately in a strictly diametrical directionwith respect to each other. Moreover some difficulty has beenexperienced in maintaining a goodly supply of grinding compound at theworking interfaces because the peripheral edges of the sections wearsharp and tend to scrape clean or block inflow of compound to theinterface working areas when progressively turned.

An improved tool for this purpose and also an improved needle lap isprovided which not only lend themselves to a novel cooperatingrelationship with improved results but also provide greatly improvedresults in the lapping performance of the lap.

It is an object of this invention to provide a tool of the aboverequirements that will retain these characteristics with a minimum ofcare and will not become damaged or inoperative during normal usage.

A further object is to provide in one tool two identical butsymmetrically opposed elements that can be used in any one of a numberof orientations in the needle eyes of laps of all sizes, including thesmallest, and when pincered with respect to each other the elementsresiliently provide a wide range of spreading distances with auniformity that is normal to the axis of the lap for each lap regardlessof its size.

A further object is to provide a needle eye lap in which ice the edgesof the semicylindrical sections are rounded to assist engagement andcooperation of the tool with a surface being lapped and further improvesthe feed of grinding compound into the working area of the engagingsurfaces as the lap is rotated progressively during its reciprocation.

Another object of the invention is to provide a tool that can be used toexpand the needle eye lap sections different distances if desired atdifferent locations along the eye, so that the lap can be adjusted as toits outside dimension at any station on its lapping surface. Forexample, portions of needle eye sections can be spread more at the heelend of the lap than at the toe end for easy entry of the lap into thehole. Then as the heel becomes worn and the lapping progresses the toeend can be increased to provide a new unworn lapping surface of the lapto contact the wall of the hole.

More particularly as distinguished from previous methods of spreadingneedle eye laps by cold chisels, wedge and anvil elements driven by ahammer or jaws of a vice that bends and distorts the lap, the presentinvention is characterized by two symmetrically matching, sharp,wedgelike edges on pincer-like jaws that are pointed towards each otherfor insertion into lap eyes without the sharp edges contacting anysurface or body that would dull them, and, if overdriven by excessiveforce will sideslip into an overlapping relationship that quicklyobstructs further movement even to the point of intentional destruction.

The invention is further characterized by the provision of bluntedcontacting portions on the mating working edges of the tool that preventthe sharp portions thereof from contacting one another and dulling. Thisfurther provides a portion which can also be used in a pincer fashion tosqueeze the eye lap sides towards each other to reduce the outsidediameter of the lap if desired.

Other objects and advantages will appear when referring to thedescription and in the following drawing in which:

FIG. 1 is an elevational assembly view of the two identical members ofthe tool as embodied in a hand type of pliers;

FIG. 2 is a sectional view of the closed position of the jaws at 22 ofFIG. 1;

FIG. 3 is an enlarged cross-sectional view of the contacting jaws ofFIG. 2;

FIG. 4 is an enlarged fragmentary perspective view of the jaws separatedand engaging a needle eye lap in phantom;

FIG. 5 is a top view of the working portion of an improved needle eyelap; and

FIG. 6 is a cross-sectional view of the needle eye lap at 6-6 of FIG. 5with the open spreading tool shown in phantom engaging the needle eye ofthe lapping tool for spreading.

Referring to FIG. 1, the assembled tool is shown and comprises twoidentical heavy sheet metal stampings 2 approximately .125" thickcomprising elongated members 4 which are pivotally connected at 6 by anydesired means such as a hollow rivet pin 8. Each member 4 comprises acurved handle portion 10 at one end, increasing in Width toward thepoint of pivotal connection 6 and a narrow neck 14 having a jaw 12thereon extending beyond the point of pivotal attachment 6 in theopposite direction of the handle 10. The jaws terminate in wedge-shapedprojections 16 and when assembled their apex edges 18 point in thedirection of closing. The side faces 26 of 3 the wedge elements 17 arethe working faces and the narrow necks 14 in combination with the tightrivet provide some resilient yield for the edges 18 to side-slip withrespect to each other in a direction radial to the pivotal connectionwhen violently overdriven towards each other. The included angle of thewedge 16 can range between 50 and 70 but preferably is 60. Such is bestsuited for the tool and purpose intended. It provides an optimum anglefor a wide spreading range for lap eyes without full closure of the jaw;confines any overlapping of the jaws edges to a very limited degree ifexcessively forced towards each other thereby eliminating any need forclosure stops; and, provides a desired shape easily and economicallyproduced in a stamping operation without tearing the metal.

The relationship between the wedges 16 of the jaws 12 when the jaws 12are closed is shown in FIGS. 2 and 3. It is seen that the apex edges 18are not parallel throughout their length but have a slight taper orrelief 20 extending from a sharp end portion 21 towards the other end 24whereby the jaws 12 contact only at the mid-portion 22 of the edges 13when closed. This slight taper is accomplished in the shearing processand remains after shaving the working faces 26 to make them smooth. Itis not necessary to grind the edge 18 to this shape although such can betouched up on a grinding wheel if desired.

FIG. 4 shows an engaging relationship of the wedges 16 of the jaws 12with a needle eye lap 28 when spreading a portion of the lap eye 29thereof. It is noted in this view that where the edges 18 are tapered inrelief, the unpointed blunt surfaces 24 are formed in the stampingoperation by the termination of the sharp ends 21 of the edges 18 at orabove the theoretical apex of the included angle 6. The sharp ends 21 ofedges 18 project the furthest and are utilized to direct the tool toenter the smallest lap eye and begin expanding the lap eye by the forceof the divergence of the working faces 26 of the wedges 16 against theinner surfaces of the lap eye. If the eye is expanded so far that thejaws 12 close, the blunt portion 24 of one wedge 16 will come in contactwith the corresponding blunt portion 24 of the opposite wedge 16 at themidportion 22 leaving the sharp leading edges 18 free of any contact,thereby retaining the sharp edges 18 for continued easy insertion intoneedle eye laps. Preferably the working faces 26 otherwise definerectangular surfaces parallel to the axis of the lap when in workingengagement with the lap eye portions 32 and 34 which will be furtherdescribed later.

Referring to FIG. 3, in conjunction with FIG. 4, it was seen that themidportions 22 of the blunt surfaces 24 are the elements which contactand stop the tool from further closing in normal use to prevent damageto the sharp end portions. The midportions 22 of the blunt surfaces 24are also used in the manner of a simple pliers to pinch the needle eyelap portions together if the lapping portions have been overspread. Thisis done by placing the portions of the needle eye lap between the bluntmidportions 22 of the Wedges 16 and applying a gripping force to thehandles 10. Thus the lap eye can be expanded and reduced as desired veryquickly and easily with minimal effort right at the site of the lappingoperations. A sufiicient force to reduce the size of the diameter of thelapping portion of the needle eye lap can be applied without causing theblunt portions 22 of the wedges 16 to damage the lapping surfaces.Furthermore, as the blunt midportions 22 of the wedges 16 are the onlyportions that make any contact, the sharp edges 18 are not made dull butremain free of contact and retain their sharpness for continued usage.

It will also be observed that the tool is manipulated mainly at rightangles to the lap thereby being usable with needle eye laps of anylength and size.

The working portion of the improved needle eye lap- 28 is shown in FIGS.and 6. Needle eye laps are formed by splitting rod stock 30diametrically from opposite sides at 38 and 40 along a portion of itslength to divide it into two identical semicylindrical portions 32 and34. The cutting dies performing the cut distort the stock from truesemicylindrical shapes and provides spaces 41 between them that tapertowards the axis of the rod and in which lapping compound can be placed.The splits at 38 and 40 also provide throats for guiding the entry ofthe spreading wedges 16 of the spreading tool, shown in dotted lines,into the cut 36 as shown in FIG. 6.

In this connection it will be observed that the edges of the notches 38and 40 have been rounded as at 42 to further widen the effective mouthof the notches 38 and 40 for easier entry of the spreading wedges 16 ofthe tool 2 into the notches 38 and 40 and these rounded edges 42 providetapering entrance portals between the wall of the hole and the toolportions 32 and 34 through which the lapping compound carried in thespaces 41 is fed between the wall of the hole and the working surfacesof the lap as the lap is turned slight increments of movement during itsreciprocation thus improving the resulting lap and reducing the timerequired to complete each lapping operation. Rapid reciprocation andprogressive turning of the needle eye lap near the terminals of thereciprocation operate to surge lapping compound in between the workingsurfaces.

From the foregoing description it will be seen that a simplepincers-type hand tool that is used in conjunction with an improvedneedle eye lap whose rounded notches aid the flow of lapping to and fromthe working areas as the lap is actuated with a unique relationshipbetween the contacting jaws that enable the tool to always retain asharp leading edge on the wedge shaped jaws by having the contact whenthe jaws are closed on a blunt relieved portion of the wedge with thefurther included means of using the blunt midportion of the wedge of thejaws as a flat surface that will not cut the lapping surface of theneedle eye lap when placed in that portion for reducing its lappingdiameter if overspread. The main advantage of this tool is itscapability to be used either as a spreader or pincer while retaining asharp edge so that one simple universally usable tool can be used inadjusting all sizes of laps.

What is claimed is:

1. A tool comprising a pair of movable members supported for relativemovement towards one another and having closable wedge shaped jaws withworking edges directed towards each other in the direction of closing,the edge of each jaw being sharp adjacent one end portion and blunt overthe remaining portion with the edges arranged asymmetrical about theirmidpoints so that when the jaws are in the closed position the sectionsof the blunt portions contact each other and the sharp end portions ofeach edge are free of any contact with the other edge.

2. A tool comprising a pair of identical movable members pivotallyattached to permit movement towards one another and having closablewedge shaped jaws pointed in the direction of closing, the edge of saidjaws having a leading sharp portion adjacent one end with a taperedrelief on the other side forming a blunt area, said blunt areas beingthe contacting surface between the edges when said jaws are in theclosed position leaving said sharp edge free from contact with anysurface.

3. A tool for use in conjunction with adjusting needle eye lapscomprising a pair of identical movable members mounted for relativepivotal movement, each of said members having a handle portion and jawportion, the jaw portions being terminally wedge shaped and their edgespointed towards each other in the direction of closing, said edges eachhaving a tapered relief over a portion of their length and a sharp edgeover the remaining length thereof, said reliefs being in contact witheach other leaving the sharp edges free from contact.

4. A pincers type tool comprising a pair of identical movable memberseach having wedge shaped jaws defin;

ing working edges and being pivotally attached for movement of theworking edge towards each other upon closure of the jaws, each edgehaving leading sharp portions disposed asymmetrically with respect toeach other when in closed position free of contact with each other, saidedges being disposed parallel to the axis of said pivotal movement.

5. A tool for adjusting needle eye laps comprising two pivotally mountedhandles with jaws, each of said jaws having terminally sharp taperedmemberspointed in the direction of closing having a taper angle ofapproximately 60, and neck means interconnecting said jaws and handlesenabling minimal overlap of said tapered members under excessive strain.

References Cited UNITED STATES PATENTS 1,840,044 1/1932 Mattes 81-425CHARLES W. LANHAM, Primary Examiner.

1. A TOOL COMPRISING A PAIR OF MOVABLE MEMBERS SUPPORTED FOR RELATIVEMOVEMENT TOWARDS ONE ANOTHER AND HAVING CLOSABLE WEDGE SHAPED JAWS WITHWORKING EDGES DIRECTED TOWARDS EACH OTHER IN THE DIRECTION OF CLOSING,THE EDGE OF EACH JAW BEING SHARP ADJACENT ONE END PORTION AND BLUNT OVERTHE REMAINING PORTION WITH THE EDGES ARRANGED ASYMMETRICAL ABOUT THEIRMIDPOINTS SO THAT WHEN THE JAWS ARE IN THE CLOSED POSITION THE SECTIONOF THE BLUNT PORTIONS CONTACT EACH OTHER AND THE SHARP END PORTIONS OFEACH EDGE ARE FREE OF ANY CONTACT WITH THE OTHER EDGE.